The owners of a Russian-backed $500 million Porters skifield development have gained final council and court approvals, saying they are now focused on a financing plan.

The project will widen the skifield facilities into the adjacent Crystal Valley, may provide about 3500 beds at the base of Porters in about 10 years and provide extra snowmaking facilities as well as hot pools.

The Craigieburn Range skifield project would give economic benefits of a similar scale to a new Auckland national convention centre or the Central Plains Water irrigation scheme, says Porters Ski Area director of development Michael Sleigh.

The early stages of the project would include an access road between Porters and Crystal Valley, but the building of that road had been put off for another year until the summer of 2013/14.

Eventually the skifields would be linked by a gondola.

Sleigh was speaking after the Environment Court gave a final tick meaning the skifield extension is included in the Selwyn District Plan.

The plan has attracted controversy, particularly because of its size and because of environmental concerns. The council private plan change (known as PC25) rezones 616 hectares of rural high country, including Crystal Valley, into a special subzone that allows skiing and development.

Selwyn District Council team leader strategy and policy David Smith said a mediated agreement to allow the Porters Ski and Recreation Area plan change had been ticked off by the court with the council informed yesterday.

One change was agreed, after an appeal by Porters Ski Area, meaning that individual buildings would only have to get one clearance for their earthquake engineering, under requirements administered by the Building Act.

"It's all operative in our district plan now . . . there's no impediment now to stop them developing their plan," Smith said.

The project is being developed by shareholders in PSA Capital, the parent company to Porters Ski Area. These stakeholders include Sydneysider Simon Harvey (with 40 per cent), and Russians Yuri Koropachinskiy and Oleg Kirillov (40 per cent), and Yury Zelvenskiy and Vladimir Uchitll (20 per cent).

Harvey said the initial access road and other preparatory work would cost in the order of $3m to $5m.

But further work, including the start of a village accommodation property, a reservoir for snowmaking, a day lodge, a gondola, chairlifts and ski trails on Crystal Valley would cost in the order of $150m.

The new ski area could be ready for the winter of 2016.

The shareholders would look at debt funding as part of the project, that has been costed at up to $500m.

"We're just going to have to complete our financial modelling," Harvey added.

The team was at the business case stage of going through all the costings and working "which bits should be built first", Sleigh added. "There's still quite a bit of work to be done . . . we've been working with quantity surveyors Rawlinsons in Christchurch."

He was also working with Simon Harvey and Dmitri Aronov, a representative of the Russian shareholders. An early part of the Crystal Valley development would be a day lodge built for several million dollars to shelter skiers for meals, refreshments and as a base for ski lessons.